Description of an enzyme-linked immunosorbent assay for the detection of protein tyrosine kinase.

A solid immunoassay for the detection of protein tyrosine kinases has been developed. It is based on the binding of the synthetic polypeptide poly(Glu.Na,Tyr) 4:1 to microELISA wells, where the phosphorylation reaction takes place in the presence of ATP and enzyme. The phosphorylated tyrosine residues produced in the reaction are finally detected, in the same well, by means of an ELISA using monoclonal antiphosphotyrosine antibody, peroxidase-labeled goat anti-mouse IgG antibody, and substrate. The amount of protein tyrosine kinase activity present in the sample is proportional to the color at 492 nm developed in each well.